Embankment for roads, railroads, and the like



Feb. 10, 1931. L. H. POPKE 1,791,840

EMBANKMENT FOR ROADS RAILROADS AND THE LIKE Filed March 9, 1927 //7 vanfor.-

Patented Feb. 10, 1 931 u NIT a srA'rssr -r LABS HARALD rorxn, orSOLLEFTEA, swnnnn EMBANKME-NT non noAns, :R-AILnoAns, Ann HE LIKE?"Application filed March 9, 1927, Serial No. 174,040; and asweaa nmn9,4926.

- This invention relates to embankments for roads, railroads and thelike in cold countries. The object of the invention is tocounteract andas far as possible prevent the wellknown rising or swelling of theembankments when the frost breaks up in spring time. 7

According to general opinion the frost in the ground is-formed in thefollowing way:

At the first stage of the frost formation the.

water present in the moist soil freezes to ice at the surface. Thereuponground water penetrates upwards on account of the capillary force and isdeposited as ice on the underside of the already formed crust. It hasalso been believed that water in the form of vapour is conveyed throughthe. cavities in the groundfrom the deeper moist layers and is condensedbelow the frozen crust due to the wellknown physical law of the coldwall. The water thus condensed is thereuponfrozen to ice by the chillfrom the outside. The frost crust is gradually growing in the last namedway causing the layers above the frost-proof V swelling occurs due tothe frost which is esdepth finally to contain considerably more waterthan the same would have been able to absorb in an unfrozen state.Thiscauses the frost to break up and the soil. becomessoft,

even practically liquid, and therefore will be less or not at all ableto withstand the pres sure exerted by vehicles, horses, etc. In thefrozen ground in winter-time also rising or pecially troublesome "inrailroad banks.

Above named disadvantages are particularly great when certain kinds ofclayare present in the ground.

As above described three differentfactors contribute to the frostformation, namely:

1. Surface water-or free'water;

3. Condensed water.

It has been tried tosreduce the, mentioned disadvantages by laying twigor sandbed:

- dings belowthe road or railroad fembank ment, therebytrying to preventthe frost from. penetrating. into the same. Experience has, however,proved that such [a method not at all or only in a verylittledegreeeliminate the said disadvantages.

I According'to this inventionthe 'disadvan- .tages of the frost areeliminated by trying to prevent the admittance ofwa'ter to the roadembankment or the like during the cold sea son, thus preventing frostformation in the foundations, etc., bylaying in the embankment or thelike at suitable depth'one or; more layers of a tight material thatdoes-not transmit water or water vapour. By this method condensed waterand capillary water are entirely prevented from penetrating 'into theembankment and form frost. The said layer should be in'the main parallelwith the above surface of the embankment so as to evenly distribute thepressure to the ground below. 7

The layers may preferably be made out of sheet iron, plane orcorrugated, or out of wood or other material that does not transmitwater or'water-vapour.

The invention is illustrated by wayof example in the accompanyingdrawing, wherein is shown a cross-section through a road embankmentprovided with one layer of a tight material.

The tightening layer l may be made out of sheet-iron, suitablygalvanized or in other way made rust-proof. It may also be made out ofother suitable'tight material. v

In order to prevent sliding of the part of the embankment above the:plate 1, the latter may be provided with angle irons 2, projections orthe like in the length direction of the] road; 7 v p The plate shown inthe figure isplane but may also be corrugated.

When embedd'ng a layerof tightfmaterial' V in the embankment inaccordance with-the invention, the road body above'the same will becomesafe "against the admittance of condensed water and'capillary water. 4The cavitiesin the ground above the tightlayer will therefore contain anordinary quantity of air. -Butfas a1r: 1n .comparlson -w1th 1ce lsavery'b'ad'heat conductor,theroadbodyboth Y I above andbelowthetight'layer will be much better insulatedagainst the chill. The chillwill be muchless able to penetrate down;

"ice. i

through-the embankment so that a consid- Q my hand.

erable decrease in the frost-proof'depth is reached. In fact the groundbelow the tight layer will also be frost-proof so that the said layerwill be embedded practically entirely in frost-proof soil. 7

Iclaim: V

A road, railroad and the like embankment consisting of an earth fillcomprising a sheet material and water impervious layer in said fillarranged substantially horizontal under the road; and a substantiallayer of earth] between the roadand'the sheet layer, said sheetlayerbeing adapted to prevent the ground moistu'reffrom creepingupwardly and depositing in the earth layer-under the road. y r V Intestimony whereof I have hereunto set LABS HARALD Po PKE.

